The turbine rotor of a gas turbine includes a rotor shaft part that extends in an axial direction with an axial line serving as the center, and a plurality of blades aligned in a peripheral direction with respect to the axial line and secured to the rotor shaft part.
The turbine rotor further includes a seal assembly for sealing off a flow of gas in the axial direction in a space between blades adjacent in the peripheral direction, in a region on the inner side in the radial direction of a platform of the blades.
Such a seal assembly is disclosed, for example, in U.S. Pat. No. 4,021,138. This seal assembly includes a seal plate that seals off a flow of gas in the axial direction in the aforementioned space, and a bolt and washer for suppressing movement of the seal plate in the peripheral direction.
An outside groove recessed outward in the radial direction and extending in the peripheral direction is formed on an end portion in the axial direction of the platform of the blade. Further, an inside groove recessed inward in the radial direction and extending in the peripheral direction is formed on the rotor shaft part in a position facing the outside groove of the blade in the radial direction.
The end portion on the outer side in the radial direction of the seal plate is fitted into the outside groove of the platform, and the end portion on the inner side in the radial direction of the seal plate is fitted into the inside groove of the rotor shaft part.